Tecciztecatl's name comes from tecciztli, the conch or snail shell, and Aztec imagery shows him wearing a shell on his back, sometimes shown emerging from it, a reference to the snail's slow, hesitant retreat into its own shelter that mirrors his four failed attempts at the fire. Where Tonatiuh, the risen sun, is depicted as young, fierce and demanding, Tecciztecatl carries associations of age, coldness, and night, an old man's deity paired against a young warrior's. Some tellings identify him closely with, or as a companion to, Metztli, the more general personification of the moon inherited from earlier central Mexican tradition, and modern scholarship is divided on whether the two names describe one figure or two overlapping ones; this atlas treats the connection as unsettled rather than deciding it.
The rabbit that dims his face is one of Mesoamerica's most widespread pieces of sky lore, told across Nahua, Maya, and other Mesoamerican traditions with local variation in exactly which god throws it and why, but consistent in reading the moon's dark patches as a rabbit's outline rather than the face familiar to European tradition. The story also does real cosmological work beyond the sun and moon: Nanahuatzin's and Tecciztecatl's mutual sacrifice explains why the Aztecs held human sacrifice to be an ongoing debt owed to the sun, since even the gods needed self-sacrifice to keep the world moving, a debt renewed by the Mexica through their own ritual bloodletting and offerings long after the mythic fire had gone out.